-40.74% is the change from 540 to 320
Calculation steps:
[( 320 - 540 ) ÷ 540] x 100 = -40.74%
Formula
Percentage change = [(320 - 540) / 540] x 100
Subtract the new number by the original number
320 - 540 = -220
-220 ÷ 540 = -0.4074074074074074
-0.4074074074074074 x 100 = -40.74%